We are studying the development of the upper aerodigestive tract which includes the oropharynx, larynx, pharynx, tongue and respiratory system in the fetus with ultrasound imaging. Pregnant women who receive care at the National Naval Medical Center are randomly selected at their regular ultrasound visits to participate in this study. The regular clinical ultrasound examination is videotaped for later analysis. Both power and color Doppler techniques are used to determine early oral pharyngeal behaviors, track amniotic fluid flow,and vascular sufficiency.Two-dimentional B-mode ultrasound images are obtained to track the growth pattern of the structures of the upper aerodigestive tract. Children who are at risk for developing abnormal feeding at birth will be carefully followed during the course of repeated studies and provided with intervention to facilitate feeding if required. We hope to develop clinical indicators that signal the possibility of aerodigestive dysfunction after birth. We have evaluated 86 fetuses(GA 15 weeks to 39 weeks) in women ages 19-42. Significant findings included the progression of suckling and other ingestive behaviors from simple to complex. Fetal swallowing primarily occurred in the presence of oral-facial stimulation. We are finding significant variations in the development and function of the ingestive system between age-matched controls and at-risk cases.